Certain Balance Sheet Components (Tables)

6 Months Ended

Jun. 30, 2021

Balance Sheet Related Disclosures [Abstract]

Accounts Receivable, Net

A summary of accounts receivable from contracts with customers is as follows:

Accounts receivable, net
In thousands	June 30, 2021		December 31, 2020
Trade receivables (net of allowance of $1,107 and $1,312)	$	286,539	$	318,269
Unbilled receivables	49,532		51,559
Total accounts receivable, net	$	336,071	$	369,828

Allowance for Credit Losses on Financing Receivables

Allowance for credit losses account activity	Three Months Ended June 30,				Six Months Ended June 30,
In thousands	2021		2020		2021		2020
Beginning balance	$	1,136	$	3,046	$	1,312	$	3,064
Provision for (release of) doubtful accounts, net	25		(171)		(42)		339
Accounts written-off	(63)		(796)		(142)		(1,211)
Effect of change in exchange rates	9		23		(21)		(90)
Ending balance	$	1,107	$	2,102	$	1,107	$	2,102

Inventories

Inventories
In thousands	June 30, 2021		December 31, 2020
Raw materials	$	117,794	$	114,058
Work in process	9,385		8,094
Finished goods	52,168		60,225
Total inventories	$	179,347	$	182,377

Property, Plant, and Equipment, Net

Property, plant, and equipment, net
In thousands	June 30, 2021		December 31, 2020
Machinery and equipment	$	335,805	$	334,050
Computers and software	117,060		115,776
Buildings, furniture, and improvements	147,764		155,676
Land	12,121		14,303
Construction in progress, including purchased equipment	36,555		31,425
Total cost	649,305		651,230
Accumulated depreciation	(453,096)		(443,414)
Property, plant, and equipment, net	$	196,209	$	207,816

Depreciation Expense

Depreciation expense	Three Months Ended June 30,				Six Months Ended June 30,
In thousands	2021		2020		2021		2020
Depreciation expense	$	12,112	$	13,059	$	24,949	$	25,925